Hopefully someone with the same set up as you sees your thread an can offer advise. I do know that over a long time the diaphragm goes slack and and the engine needs tuning. A neighbour's vehicle had all kinds of problems with wires that weren't crimped properly. Also spade lugs can feel tight but can get a layer of carbon under the contacts. I had to re-crimp all the conversion wires and use pliers to tighten the spade lugs before his car ran properly.